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ac79cbb9 | 1 | /* Copyright (C) 2011-2017 B.A.T.M.A.N. contributors: |
785ea114 AQ |
2 | * |
3 | * Antonio Quartulli | |
4 | * | |
5 | * This program is free software; you can redistribute it and/or | |
6 | * modify it under the terms of version 2 of the GNU General Public | |
7 | * License as published by the Free Software Foundation. | |
8 | * | |
9 | * This program is distributed in the hope that it will be useful, but | |
10 | * WITHOUT ANY WARRANTY; without even the implied warranty of | |
11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
12 | * General Public License for more details. | |
13 | * | |
14 | * You should have received a copy of the GNU General Public License | |
ebf38fb7 | 15 | * along with this program; if not, see <http://www.gnu.org/licenses/>. |
785ea114 AQ |
16 | */ |
17 | ||
1e2c2a4f SE |
18 | #include "distributed-arp-table.h" |
19 | #include "main.h" | |
20 | ||
21 | #include <linux/atomic.h> | |
65d7d460 | 22 | #include <linux/bitops.h> |
1e2c2a4f SE |
23 | #include <linux/byteorder/generic.h> |
24 | #include <linux/errno.h> | |
25 | #include <linux/etherdevice.h> | |
26 | #include <linux/fs.h> | |
785ea114 | 27 | #include <linux/if_arp.h> |
1e2c2a4f | 28 | #include <linux/if_ether.h> |
be1db4f6 | 29 | #include <linux/if_vlan.h> |
1e2c2a4f SE |
30 | #include <linux/in.h> |
31 | #include <linux/jiffies.h> | |
32 | #include <linux/kernel.h> | |
68a6722c | 33 | #include <linux/kref.h> |
1e2c2a4f SE |
34 | #include <linux/list.h> |
35 | #include <linux/rculist.h> | |
36 | #include <linux/rcupdate.h> | |
37 | #include <linux/seq_file.h> | |
38 | #include <linux/skbuff.h> | |
39 | #include <linux/slab.h> | |
40 | #include <linux/spinlock.h> | |
41 | #include <linux/stddef.h> | |
42 | #include <linux/string.h> | |
43 | #include <linux/workqueue.h> | |
c384ea3e | 44 | #include <net/arp.h> |
785ea114 | 45 | |
00311de5 | 46 | #include "bridge_loop_avoidance.h" |
785ea114 | 47 | #include "hard-interface.h" |
1e2c2a4f | 48 | #include "hash.h" |
ba412080 | 49 | #include "log.h" |
785ea114 AQ |
50 | #include "originator.h" |
51 | #include "send.h" | |
c384ea3e | 52 | #include "translation-table.h" |
1f8dce49 | 53 | #include "tvlv.h" |
785ea114 | 54 | |
2f1dfbe1 AQ |
55 | static void batadv_dat_purge(struct work_struct *work); |
56 | ||
57 | /** | |
58 | * batadv_dat_start_timer - initialise the DAT periodic worker | |
59 | * @bat_priv: the bat priv with all the soft interface information | |
60 | */ | |
61 | static void batadv_dat_start_timer(struct batadv_priv *bat_priv) | |
62 | { | |
63 | INIT_DELAYED_WORK(&bat_priv->dat.work, batadv_dat_purge); | |
64 | queue_delayed_work(batadv_event_workqueue, &bat_priv->dat.work, | |
65 | msecs_to_jiffies(10000)); | |
66 | } | |
67 | ||
68a6722c SE |
68 | /** |
69 | * batadv_dat_entry_release - release dat_entry from lists and queue for free | |
70 | * after rcu grace period | |
71 | * @ref: kref pointer of the dat_entry | |
72 | */ | |
73 | static void batadv_dat_entry_release(struct kref *ref) | |
74 | { | |
75 | struct batadv_dat_entry *dat_entry; | |
76 | ||
77 | dat_entry = container_of(ref, struct batadv_dat_entry, refcount); | |
78 | ||
79 | kfree_rcu(dat_entry, rcu); | |
80 | } | |
81 | ||
2f1dfbe1 | 82 | /** |
a6416f9f | 83 | * batadv_dat_entry_put - decrement the dat_entry refcounter and possibly |
68a6722c SE |
84 | * release it |
85 | * @dat_entry: dat_entry to be free'd | |
2f1dfbe1 | 86 | */ |
a6416f9f | 87 | static void batadv_dat_entry_put(struct batadv_dat_entry *dat_entry) |
2f1dfbe1 | 88 | { |
68a6722c | 89 | kref_put(&dat_entry->refcount, batadv_dat_entry_release); |
2f1dfbe1 AQ |
90 | } |
91 | ||
92 | /** | |
93178018 | 93 | * batadv_dat_to_purge - check whether a dat_entry has to be purged or not |
2f1dfbe1 AQ |
94 | * @dat_entry: the entry to check |
95 | * | |
62fe710f | 96 | * Return: true if the entry has to be purged now, false otherwise. |
2f1dfbe1 AQ |
97 | */ |
98 | static bool batadv_dat_to_purge(struct batadv_dat_entry *dat_entry) | |
99 | { | |
100 | return batadv_has_timed_out(dat_entry->last_update, | |
101 | BATADV_DAT_ENTRY_TIMEOUT); | |
102 | } | |
103 | ||
104 | /** | |
105 | * __batadv_dat_purge - delete entries from the DAT local storage | |
106 | * @bat_priv: the bat priv with all the soft interface information | |
107 | * @to_purge: function in charge to decide whether an entry has to be purged or | |
108 | * not. This function takes the dat_entry as argument and has to | |
109 | * returns a boolean value: true is the entry has to be deleted, | |
110 | * false otherwise | |
111 | * | |
93178018 ML |
112 | * Loops over each entry in the DAT local storage and deletes it if and only if |
113 | * the to_purge function passed as argument returns true. | |
2f1dfbe1 AQ |
114 | */ |
115 | static void __batadv_dat_purge(struct batadv_priv *bat_priv, | |
116 | bool (*to_purge)(struct batadv_dat_entry *)) | |
117 | { | |
118 | spinlock_t *list_lock; /* protects write access to the hash lists */ | |
119 | struct batadv_dat_entry *dat_entry; | |
b67bfe0d | 120 | struct hlist_node *node_tmp; |
2f1dfbe1 | 121 | struct hlist_head *head; |
6b5e971a | 122 | u32 i; |
2f1dfbe1 AQ |
123 | |
124 | if (!bat_priv->dat.hash) | |
125 | return; | |
126 | ||
127 | for (i = 0; i < bat_priv->dat.hash->size; i++) { | |
128 | head = &bat_priv->dat.hash->table[i]; | |
129 | list_lock = &bat_priv->dat.hash->list_locks[i]; | |
130 | ||
131 | spin_lock_bh(list_lock); | |
b67bfe0d | 132 | hlist_for_each_entry_safe(dat_entry, node_tmp, head, |
2f1dfbe1 | 133 | hash_entry) { |
93178018 | 134 | /* if a helper function has been passed as parameter, |
2f1dfbe1 AQ |
135 | * ask it if the entry has to be purged or not |
136 | */ | |
137 | if (to_purge && !to_purge(dat_entry)) | |
138 | continue; | |
139 | ||
b67bfe0d | 140 | hlist_del_rcu(&dat_entry->hash_entry); |
a6416f9f | 141 | batadv_dat_entry_put(dat_entry); |
2f1dfbe1 AQ |
142 | } |
143 | spin_unlock_bh(list_lock); | |
144 | } | |
145 | } | |
146 | ||
147 | /** | |
148 | * batadv_dat_purge - periodic task that deletes old entries from the local DAT | |
149 | * hash table | |
150 | * @work: kernel work struct | |
151 | */ | |
152 | static void batadv_dat_purge(struct work_struct *work) | |
153 | { | |
154 | struct delayed_work *delayed_work; | |
155 | struct batadv_priv_dat *priv_dat; | |
156 | struct batadv_priv *bat_priv; | |
157 | ||
4ba4bc0f | 158 | delayed_work = to_delayed_work(work); |
2f1dfbe1 AQ |
159 | priv_dat = container_of(delayed_work, struct batadv_priv_dat, work); |
160 | bat_priv = container_of(priv_dat, struct batadv_priv, dat); | |
161 | ||
162 | __batadv_dat_purge(bat_priv, batadv_dat_to_purge); | |
163 | batadv_dat_start_timer(bat_priv); | |
164 | } | |
165 | ||
166 | /** | |
167 | * batadv_compare_dat - comparing function used in the local DAT hash table | |
168 | * @node: node in the local table | |
169 | * @data2: second object to compare the node to | |
170 | * | |
4b426b10 | 171 | * Return: true if the two entries are the same, false otherwise. |
2f1dfbe1 | 172 | */ |
4b426b10 | 173 | static bool batadv_compare_dat(const struct hlist_node *node, const void *data2) |
2f1dfbe1 AQ |
174 | { |
175 | const void *data1 = container_of(node, struct batadv_dat_entry, | |
176 | hash_entry); | |
177 | ||
4b426b10 | 178 | return memcmp(data1, data2, sizeof(__be32)) == 0; |
2f1dfbe1 AQ |
179 | } |
180 | ||
5c3a0e55 AQ |
181 | /** |
182 | * batadv_arp_hw_src - extract the hw_src field from an ARP packet | |
183 | * @skb: ARP packet | |
184 | * @hdr_size: size of the possible header before the ARP packet | |
185 | * | |
62fe710f | 186 | * Return: the value of the hw_src field in the ARP packet. |
5c3a0e55 | 187 | */ |
6b5e971a | 188 | static u8 *batadv_arp_hw_src(struct sk_buff *skb, int hdr_size) |
5c3a0e55 | 189 | { |
6b5e971a | 190 | u8 *addr; |
5c3a0e55 | 191 | |
6b5e971a | 192 | addr = (u8 *)(skb->data + hdr_size); |
5c3a0e55 AQ |
193 | addr += ETH_HLEN + sizeof(struct arphdr); |
194 | ||
195 | return addr; | |
196 | } | |
197 | ||
198 | /** | |
199 | * batadv_arp_ip_src - extract the ip_src field from an ARP packet | |
200 | * @skb: ARP packet | |
201 | * @hdr_size: size of the possible header before the ARP packet | |
202 | * | |
62fe710f | 203 | * Return: the value of the ip_src field in the ARP packet. |
5c3a0e55 AQ |
204 | */ |
205 | static __be32 batadv_arp_ip_src(struct sk_buff *skb, int hdr_size) | |
206 | { | |
207 | return *(__be32 *)(batadv_arp_hw_src(skb, hdr_size) + ETH_ALEN); | |
208 | } | |
209 | ||
210 | /** | |
211 | * batadv_arp_hw_dst - extract the hw_dst field from an ARP packet | |
212 | * @skb: ARP packet | |
213 | * @hdr_size: size of the possible header before the ARP packet | |
214 | * | |
62fe710f | 215 | * Return: the value of the hw_dst field in the ARP packet. |
5c3a0e55 | 216 | */ |
6b5e971a | 217 | static u8 *batadv_arp_hw_dst(struct sk_buff *skb, int hdr_size) |
5c3a0e55 AQ |
218 | { |
219 | return batadv_arp_hw_src(skb, hdr_size) + ETH_ALEN + 4; | |
220 | } | |
221 | ||
222 | /** | |
223 | * batadv_arp_ip_dst - extract the ip_dst field from an ARP packet | |
224 | * @skb: ARP packet | |
225 | * @hdr_size: size of the possible header before the ARP packet | |
226 | * | |
62fe710f | 227 | * Return: the value of the ip_dst field in the ARP packet. |
5c3a0e55 AQ |
228 | */ |
229 | static __be32 batadv_arp_ip_dst(struct sk_buff *skb, int hdr_size) | |
230 | { | |
231 | return *(__be32 *)(batadv_arp_hw_src(skb, hdr_size) + ETH_ALEN * 2 + 4); | |
232 | } | |
233 | ||
785ea114 AQ |
234 | /** |
235 | * batadv_hash_dat - compute the hash value for an IP address | |
236 | * @data: data to hash | |
237 | * @size: size of the hash table | |
238 | * | |
62fe710f | 239 | * Return: the selected index in the hash table for the given data. |
785ea114 | 240 | */ |
6b5e971a | 241 | static u32 batadv_hash_dat(const void *data, u32 size) |
785ea114 | 242 | { |
6b5e971a | 243 | u32 hash = 0; |
be1db4f6 | 244 | const struct batadv_dat_entry *dat = data; |
36fd61cb | 245 | const unsigned char *key; |
6b5e971a | 246 | u32 i; |
36fd61cb SE |
247 | |
248 | key = (const unsigned char *)&dat->ip; | |
249 | for (i = 0; i < sizeof(dat->ip); i++) { | |
250 | hash += key[i]; | |
251 | hash += (hash << 10); | |
252 | hash ^= (hash >> 6); | |
253 | } | |
785ea114 | 254 | |
36fd61cb SE |
255 | key = (const unsigned char *)&dat->vid; |
256 | for (i = 0; i < sizeof(dat->vid); i++) { | |
257 | hash += key[i]; | |
258 | hash += (hash << 10); | |
259 | hash ^= (hash >> 6); | |
260 | } | |
785ea114 AQ |
261 | |
262 | hash += (hash << 3); | |
263 | hash ^= (hash >> 11); | |
264 | hash += (hash << 15); | |
265 | ||
266 | return hash % size; | |
267 | } | |
268 | ||
2f1dfbe1 | 269 | /** |
93178018 | 270 | * batadv_dat_entry_hash_find - look for a given dat_entry in the local hash |
2f1dfbe1 AQ |
271 | * table |
272 | * @bat_priv: the bat priv with all the soft interface information | |
273 | * @ip: search key | |
be1db4f6 | 274 | * @vid: VLAN identifier |
2f1dfbe1 | 275 | * |
62fe710f | 276 | * Return: the dat_entry if found, NULL otherwise. |
2f1dfbe1 AQ |
277 | */ |
278 | static struct batadv_dat_entry * | |
be1db4f6 AQ |
279 | batadv_dat_entry_hash_find(struct batadv_priv *bat_priv, __be32 ip, |
280 | unsigned short vid) | |
2f1dfbe1 AQ |
281 | { |
282 | struct hlist_head *head; | |
be1db4f6 | 283 | struct batadv_dat_entry to_find, *dat_entry, *dat_entry_tmp = NULL; |
2f1dfbe1 | 284 | struct batadv_hashtable *hash = bat_priv->dat.hash; |
6b5e971a | 285 | u32 index; |
2f1dfbe1 AQ |
286 | |
287 | if (!hash) | |
288 | return NULL; | |
289 | ||
be1db4f6 AQ |
290 | to_find.ip = ip; |
291 | to_find.vid = vid; | |
292 | ||
293 | index = batadv_hash_dat(&to_find, hash->size); | |
2f1dfbe1 AQ |
294 | head = &hash->table[index]; |
295 | ||
296 | rcu_read_lock(); | |
b67bfe0d | 297 | hlist_for_each_entry_rcu(dat_entry, head, hash_entry) { |
2f1dfbe1 AQ |
298 | if (dat_entry->ip != ip) |
299 | continue; | |
300 | ||
68a6722c | 301 | if (!kref_get_unless_zero(&dat_entry->refcount)) |
2f1dfbe1 AQ |
302 | continue; |
303 | ||
304 | dat_entry_tmp = dat_entry; | |
305 | break; | |
306 | } | |
307 | rcu_read_unlock(); | |
308 | ||
309 | return dat_entry_tmp; | |
310 | } | |
311 | ||
312 | /** | |
313 | * batadv_dat_entry_add - add a new dat entry or update it if already exists | |
314 | * @bat_priv: the bat priv with all the soft interface information | |
315 | * @ip: ipv4 to add/edit | |
316 | * @mac_addr: mac address to assign to the given ipv4 | |
be1db4f6 | 317 | * @vid: VLAN identifier |
2f1dfbe1 AQ |
318 | */ |
319 | static void batadv_dat_entry_add(struct batadv_priv *bat_priv, __be32 ip, | |
6b5e971a | 320 | u8 *mac_addr, unsigned short vid) |
2f1dfbe1 AQ |
321 | { |
322 | struct batadv_dat_entry *dat_entry; | |
323 | int hash_added; | |
324 | ||
be1db4f6 | 325 | dat_entry = batadv_dat_entry_hash_find(bat_priv, ip, vid); |
2f1dfbe1 AQ |
326 | /* if this entry is already known, just update it */ |
327 | if (dat_entry) { | |
328 | if (!batadv_compare_eth(dat_entry->mac_addr, mac_addr)) | |
8fdd0153 | 329 | ether_addr_copy(dat_entry->mac_addr, mac_addr); |
2f1dfbe1 AQ |
330 | dat_entry->last_update = jiffies; |
331 | batadv_dbg(BATADV_DBG_DAT, bat_priv, | |
be1db4f6 AQ |
332 | "Entry updated: %pI4 %pM (vid: %d)\n", |
333 | &dat_entry->ip, dat_entry->mac_addr, | |
f7a2bd65 | 334 | batadv_print_vid(vid)); |
2f1dfbe1 AQ |
335 | goto out; |
336 | } | |
337 | ||
338 | dat_entry = kmalloc(sizeof(*dat_entry), GFP_ATOMIC); | |
339 | if (!dat_entry) | |
340 | goto out; | |
341 | ||
342 | dat_entry->ip = ip; | |
be1db4f6 | 343 | dat_entry->vid = vid; |
8fdd0153 | 344 | ether_addr_copy(dat_entry->mac_addr, mac_addr); |
2f1dfbe1 | 345 | dat_entry->last_update = jiffies; |
68a6722c | 346 | kref_init(&dat_entry->refcount); |
2f1dfbe1 | 347 | |
6a51e09d | 348 | kref_get(&dat_entry->refcount); |
2f1dfbe1 | 349 | hash_added = batadv_hash_add(bat_priv->dat.hash, batadv_compare_dat, |
be1db4f6 | 350 | batadv_hash_dat, dat_entry, |
2f1dfbe1 AQ |
351 | &dat_entry->hash_entry); |
352 | ||
353 | if (unlikely(hash_added != 0)) { | |
354 | /* remove the reference for the hash */ | |
a6416f9f | 355 | batadv_dat_entry_put(dat_entry); |
2f1dfbe1 AQ |
356 | goto out; |
357 | } | |
358 | ||
be1db4f6 | 359 | batadv_dbg(BATADV_DBG_DAT, bat_priv, "New entry added: %pI4 %pM (vid: %d)\n", |
f7a2bd65 | 360 | &dat_entry->ip, dat_entry->mac_addr, batadv_print_vid(vid)); |
2f1dfbe1 AQ |
361 | |
362 | out: | |
363 | if (dat_entry) | |
a6416f9f | 364 | batadv_dat_entry_put(dat_entry); |
2f1dfbe1 AQ |
365 | } |
366 | ||
5c3a0e55 AQ |
367 | #ifdef CONFIG_BATMAN_ADV_DEBUG |
368 | ||
369 | /** | |
370 | * batadv_dbg_arp - print a debug message containing all the ARP packet details | |
371 | * @bat_priv: the bat priv with all the soft interface information | |
372 | * @skb: ARP packet | |
5c3a0e55 AQ |
373 | * @hdr_size: size of the possible header before the ARP packet |
374 | * @msg: message to print together with the debugging information | |
375 | */ | |
376 | static void batadv_dbg_arp(struct batadv_priv *bat_priv, struct sk_buff *skb, | |
843314c9 | 377 | int hdr_size, char *msg) |
5c3a0e55 AQ |
378 | { |
379 | struct batadv_unicast_4addr_packet *unicast_4addr_packet; | |
380 | struct batadv_bcast_packet *bcast_pkt; | |
6b5e971a | 381 | u8 *orig_addr; |
5c3a0e55 AQ |
382 | __be32 ip_src, ip_dst; |
383 | ||
384 | if (msg) | |
385 | batadv_dbg(BATADV_DBG_DAT, bat_priv, "%s\n", msg); | |
386 | ||
387 | ip_src = batadv_arp_ip_src(skb, hdr_size); | |
388 | ip_dst = batadv_arp_ip_dst(skb, hdr_size); | |
389 | batadv_dbg(BATADV_DBG_DAT, bat_priv, | |
390 | "ARP MSG = [src: %pM-%pI4 dst: %pM-%pI4]\n", | |
391 | batadv_arp_hw_src(skb, hdr_size), &ip_src, | |
392 | batadv_arp_hw_dst(skb, hdr_size), &ip_dst); | |
393 | ||
394 | if (hdr_size == 0) | |
395 | return; | |
396 | ||
5c3a0e55 AQ |
397 | unicast_4addr_packet = (struct batadv_unicast_4addr_packet *)skb->data; |
398 | ||
a40d9b07 | 399 | switch (unicast_4addr_packet->u.packet_type) { |
5c3a0e55 AQ |
400 | case BATADV_UNICAST: |
401 | batadv_dbg(BATADV_DBG_DAT, bat_priv, | |
402 | "* encapsulated within a UNICAST packet\n"); | |
403 | break; | |
404 | case BATADV_UNICAST_4ADDR: | |
405 | batadv_dbg(BATADV_DBG_DAT, bat_priv, | |
406 | "* encapsulated within a UNICAST_4ADDR packet (src: %pM)\n", | |
407 | unicast_4addr_packet->src); | |
408 | switch (unicast_4addr_packet->subtype) { | |
409 | case BATADV_P_DAT_DHT_PUT: | |
410 | batadv_dbg(BATADV_DBG_DAT, bat_priv, "* type: DAT_DHT_PUT\n"); | |
411 | break; | |
412 | case BATADV_P_DAT_DHT_GET: | |
413 | batadv_dbg(BATADV_DBG_DAT, bat_priv, "* type: DAT_DHT_GET\n"); | |
414 | break; | |
415 | case BATADV_P_DAT_CACHE_REPLY: | |
416 | batadv_dbg(BATADV_DBG_DAT, bat_priv, | |
417 | "* type: DAT_CACHE_REPLY\n"); | |
418 | break; | |
419 | case BATADV_P_DATA: | |
420 | batadv_dbg(BATADV_DBG_DAT, bat_priv, "* type: DATA\n"); | |
421 | break; | |
422 | default: | |
423 | batadv_dbg(BATADV_DBG_DAT, bat_priv, "* type: Unknown (%u)!\n", | |
a40d9b07 | 424 | unicast_4addr_packet->u.packet_type); |
5c3a0e55 AQ |
425 | } |
426 | break; | |
427 | case BATADV_BCAST: | |
428 | bcast_pkt = (struct batadv_bcast_packet *)unicast_4addr_packet; | |
429 | orig_addr = bcast_pkt->orig; | |
430 | batadv_dbg(BATADV_DBG_DAT, bat_priv, | |
431 | "* encapsulated within a BCAST packet (src: %pM)\n", | |
432 | orig_addr); | |
433 | break; | |
434 | default: | |
435 | batadv_dbg(BATADV_DBG_DAT, bat_priv, | |
436 | "* encapsulated within an unknown packet type (0x%x)\n", | |
a40d9b07 | 437 | unicast_4addr_packet->u.packet_type); |
5c3a0e55 AQ |
438 | } |
439 | } | |
440 | ||
441 | #else | |
442 | ||
443 | static void batadv_dbg_arp(struct batadv_priv *bat_priv, struct sk_buff *skb, | |
843314c9 | 444 | int hdr_size, char *msg) |
5c3a0e55 AQ |
445 | { |
446 | } | |
447 | ||
448 | #endif /* CONFIG_BATMAN_ADV_DEBUG */ | |
449 | ||
785ea114 AQ |
450 | /** |
451 | * batadv_is_orig_node_eligible - check whether a node can be a DHT candidate | |
452 | * @res: the array with the already selected candidates | |
453 | * @select: number of already selected candidates | |
454 | * @tmp_max: address of the currently evaluated node | |
455 | * @max: current round max address | |
456 | * @last_max: address of the last selected candidate | |
457 | * @candidate: orig_node under evaluation | |
458 | * @max_orig_node: last selected candidate | |
459 | * | |
62fe710f | 460 | * Return: true if the node has been elected as next candidate or false |
93178018 | 461 | * otherwise. |
785ea114 AQ |
462 | */ |
463 | static bool batadv_is_orig_node_eligible(struct batadv_dat_candidate *res, | |
464 | int select, batadv_dat_addr_t tmp_max, | |
465 | batadv_dat_addr_t max, | |
466 | batadv_dat_addr_t last_max, | |
467 | struct batadv_orig_node *candidate, | |
468 | struct batadv_orig_node *max_orig_node) | |
469 | { | |
470 | bool ret = false; | |
471 | int j; | |
472 | ||
17cf0ea4 | 473 | /* check if orig node candidate is running DAT */ |
65d7d460 | 474 | if (!test_bit(BATADV_ORIG_CAPA_HAS_DAT, &candidate->capabilities)) |
17cf0ea4 ML |
475 | goto out; |
476 | ||
785ea114 AQ |
477 | /* Check if this node has already been selected... */ |
478 | for (j = 0; j < select; j++) | |
479 | if (res[j].orig_node == candidate) | |
480 | break; | |
481 | /* ..and possibly skip it */ | |
482 | if (j < select) | |
483 | goto out; | |
484 | /* sanity check: has it already been selected? This should not happen */ | |
485 | if (tmp_max > last_max) | |
486 | goto out; | |
487 | /* check if during this iteration an originator with a closer dht | |
488 | * address has already been found | |
489 | */ | |
490 | if (tmp_max < max) | |
491 | goto out; | |
492 | /* this is an hash collision with the temporary selected node. Choose | |
493 | * the one with the lowest address | |
494 | */ | |
816cd5b8 | 495 | if ((tmp_max == max) && max_orig_node && |
785ea114 AQ |
496 | (batadv_compare_eth(candidate->orig, max_orig_node->orig) > 0)) |
497 | goto out; | |
498 | ||
499 | ret = true; | |
500 | out: | |
501 | return ret; | |
502 | } | |
503 | ||
504 | /** | |
505 | * batadv_choose_next_candidate - select the next DHT candidate | |
506 | * @bat_priv: the bat priv with all the soft interface information | |
507 | * @cands: candidates array | |
508 | * @select: number of candidates already present in the array | |
509 | * @ip_key: key to look up in the DHT | |
510 | * @last_max: pointer where the address of the selected candidate will be saved | |
511 | */ | |
512 | static void batadv_choose_next_candidate(struct batadv_priv *bat_priv, | |
513 | struct batadv_dat_candidate *cands, | |
514 | int select, batadv_dat_addr_t ip_key, | |
515 | batadv_dat_addr_t *last_max) | |
516 | { | |
4f248cff SE |
517 | batadv_dat_addr_t max = 0; |
518 | batadv_dat_addr_t tmp_max = 0; | |
785ea114 AQ |
519 | struct batadv_orig_node *orig_node, *max_orig_node = NULL; |
520 | struct batadv_hashtable *hash = bat_priv->orig_hash; | |
785ea114 AQ |
521 | struct hlist_head *head; |
522 | int i; | |
523 | ||
524 | /* if no node is eligible as candidate, leave the candidate type as | |
525 | * NOT_FOUND | |
526 | */ | |
527 | cands[select].type = BATADV_DAT_CANDIDATE_NOT_FOUND; | |
528 | ||
93178018 | 529 | /* iterate over the originator list and find the node with the closest |
785ea114 AQ |
530 | * dat_address which has not been selected yet |
531 | */ | |
532 | for (i = 0; i < hash->size; i++) { | |
533 | head = &hash->table[i]; | |
534 | ||
535 | rcu_read_lock(); | |
b67bfe0d | 536 | hlist_for_each_entry_rcu(orig_node, head, hash_entry) { |
93178018 | 537 | /* the dht space is a ring using unsigned addresses */ |
785ea114 AQ |
538 | tmp_max = BATADV_DAT_ADDR_MAX - orig_node->dat_addr + |
539 | ip_key; | |
540 | ||
541 | if (!batadv_is_orig_node_eligible(cands, select, | |
542 | tmp_max, max, | |
543 | *last_max, orig_node, | |
544 | max_orig_node)) | |
545 | continue; | |
546 | ||
7c124391 | 547 | if (!kref_get_unless_zero(&orig_node->refcount)) |
785ea114 AQ |
548 | continue; |
549 | ||
550 | max = tmp_max; | |
551 | if (max_orig_node) | |
5d967310 | 552 | batadv_orig_node_put(max_orig_node); |
785ea114 AQ |
553 | max_orig_node = orig_node; |
554 | } | |
555 | rcu_read_unlock(); | |
556 | } | |
557 | if (max_orig_node) { | |
558 | cands[select].type = BATADV_DAT_CANDIDATE_ORIG; | |
559 | cands[select].orig_node = max_orig_node; | |
560 | batadv_dbg(BATADV_DBG_DAT, bat_priv, | |
561 | "dat_select_candidates() %d: selected %pM addr=%u dist=%u\n", | |
562 | select, max_orig_node->orig, max_orig_node->dat_addr, | |
563 | max); | |
564 | } | |
565 | *last_max = max; | |
566 | } | |
567 | ||
568 | /** | |
93178018 | 569 | * batadv_dat_select_candidates - select the nodes which the DHT message has to |
785ea114 AQ |
570 | * be sent to |
571 | * @bat_priv: the bat priv with all the soft interface information | |
572 | * @ip_dst: ipv4 to look up in the DHT | |
2871734e | 573 | * @vid: VLAN identifier |
785ea114 AQ |
574 | * |
575 | * An originator O is selected if and only if its DHT_ID value is one of three | |
576 | * closest values (from the LEFT, with wrap around if needed) then the hash | |
577 | * value of the key. ip_dst is the key. | |
578 | * | |
62fe710f | 579 | * Return: the candidate array of size BATADV_DAT_CANDIDATE_NUM. |
785ea114 AQ |
580 | */ |
581 | static struct batadv_dat_candidate * | |
2871734e AQ |
582 | batadv_dat_select_candidates(struct batadv_priv *bat_priv, __be32 ip_dst, |
583 | unsigned short vid) | |
785ea114 AQ |
584 | { |
585 | int select; | |
586 | batadv_dat_addr_t last_max = BATADV_DAT_ADDR_MAX, ip_key; | |
587 | struct batadv_dat_candidate *res; | |
b7fe3d4f | 588 | struct batadv_dat_entry dat; |
785ea114 AQ |
589 | |
590 | if (!bat_priv->orig_hash) | |
591 | return NULL; | |
592 | ||
0185dda6 AQ |
593 | res = kmalloc_array(BATADV_DAT_CANDIDATES_NUM, sizeof(*res), |
594 | GFP_ATOMIC); | |
785ea114 AQ |
595 | if (!res) |
596 | return NULL; | |
597 | ||
b7fe3d4f | 598 | dat.ip = ip_dst; |
2871734e | 599 | dat.vid = vid; |
b7fe3d4f | 600 | ip_key = (batadv_dat_addr_t)batadv_hash_dat(&dat, |
785ea114 AQ |
601 | BATADV_DAT_ADDR_MAX); |
602 | ||
603 | batadv_dbg(BATADV_DBG_DAT, bat_priv, | |
22f0502e | 604 | "%s(): IP=%pI4 hash(IP)=%u\n", __func__, &ip_dst, |
785ea114 AQ |
605 | ip_key); |
606 | ||
607 | for (select = 0; select < BATADV_DAT_CANDIDATES_NUM; select++) | |
608 | batadv_choose_next_candidate(bat_priv, res, select, ip_key, | |
609 | &last_max); | |
610 | ||
611 | return res; | |
612 | } | |
613 | ||
614 | /** | |
615 | * batadv_dat_send_data - send a payload to the selected candidates | |
616 | * @bat_priv: the bat priv with all the soft interface information | |
617 | * @skb: payload to send | |
618 | * @ip: the DHT key | |
2871734e | 619 | * @vid: VLAN identifier |
785ea114 AQ |
620 | * @packet_subtype: unicast4addr packet subtype to use |
621 | * | |
93178018 ML |
622 | * This function copies the skb with pskb_copy() and is sent as unicast packet |
623 | * to each of the selected candidates. | |
785ea114 | 624 | * |
62fe710f | 625 | * Return: true if the packet is sent to at least one candidate, false |
93178018 | 626 | * otherwise. |
785ea114 AQ |
627 | */ |
628 | static bool batadv_dat_send_data(struct batadv_priv *bat_priv, | |
629 | struct sk_buff *skb, __be32 ip, | |
2871734e | 630 | unsigned short vid, int packet_subtype) |
785ea114 AQ |
631 | { |
632 | int i; | |
633 | bool ret = false; | |
634 | int send_status; | |
635 | struct batadv_neigh_node *neigh_node = NULL; | |
636 | struct sk_buff *tmp_skb; | |
637 | struct batadv_dat_candidate *cand; | |
638 | ||
2871734e | 639 | cand = batadv_dat_select_candidates(bat_priv, ip, vid); |
785ea114 AQ |
640 | if (!cand) |
641 | goto out; | |
642 | ||
643 | batadv_dbg(BATADV_DBG_DAT, bat_priv, "DHT_SEND for %pI4\n", &ip); | |
644 | ||
645 | for (i = 0; i < BATADV_DAT_CANDIDATES_NUM; i++) { | |
646 | if (cand[i].type == BATADV_DAT_CANDIDATE_NOT_FOUND) | |
647 | continue; | |
648 | ||
7351a482 SW |
649 | neigh_node = batadv_orig_router_get(cand[i].orig_node, |
650 | BATADV_IF_DEFAULT); | |
785ea114 AQ |
651 | if (!neigh_node) |
652 | goto free_orig; | |
653 | ||
bad93e9d | 654 | tmp_skb = pskb_copy_for_clone(skb, GFP_ATOMIC); |
f097e25d MH |
655 | if (!batadv_send_skb_prepare_unicast_4addr(bat_priv, tmp_skb, |
656 | cand[i].orig_node, | |
657 | packet_subtype)) { | |
785ea114 AQ |
658 | kfree_skb(tmp_skb); |
659 | goto free_neigh; | |
660 | } | |
661 | ||
95d39278 | 662 | send_status = batadv_send_unicast_skb(tmp_skb, neigh_node); |
4046b24a MH |
663 | if (send_status == NET_XMIT_SUCCESS) { |
664 | /* count the sent packet */ | |
665 | switch (packet_subtype) { | |
666 | case BATADV_P_DAT_DHT_GET: | |
667 | batadv_inc_counter(bat_priv, | |
668 | BATADV_CNT_DAT_GET_TX); | |
669 | break; | |
670 | case BATADV_P_DAT_DHT_PUT: | |
671 | batadv_inc_counter(bat_priv, | |
672 | BATADV_CNT_DAT_PUT_TX); | |
673 | break; | |
674 | } | |
675 | ||
785ea114 AQ |
676 | /* packet sent to a candidate: return true */ |
677 | ret = true; | |
4046b24a | 678 | } |
785ea114 | 679 | free_neigh: |
25bb2509 | 680 | batadv_neigh_node_put(neigh_node); |
785ea114 | 681 | free_orig: |
5d967310 | 682 | batadv_orig_node_put(cand[i].orig_node); |
785ea114 AQ |
683 | } |
684 | ||
685 | out: | |
686 | kfree(cand); | |
687 | return ret; | |
688 | } | |
2f1dfbe1 | 689 | |
17cf0ea4 ML |
690 | /** |
691 | * batadv_dat_tvlv_container_update - update the dat tvlv container after dat | |
692 | * setting change | |
693 | * @bat_priv: the bat priv with all the soft interface information | |
694 | */ | |
695 | static void batadv_dat_tvlv_container_update(struct batadv_priv *bat_priv) | |
696 | { | |
697 | char dat_mode; | |
698 | ||
699 | dat_mode = atomic_read(&bat_priv->distributed_arp_table); | |
700 | ||
701 | switch (dat_mode) { | |
702 | case 0: | |
703 | batadv_tvlv_container_unregister(bat_priv, BATADV_TVLV_DAT, 1); | |
704 | break; | |
705 | case 1: | |
706 | batadv_tvlv_container_register(bat_priv, BATADV_TVLV_DAT, 1, | |
707 | NULL, 0); | |
708 | break; | |
709 | } | |
710 | } | |
711 | ||
712 | /** | |
713 | * batadv_dat_status_update - update the dat tvlv container after dat | |
714 | * setting change | |
715 | * @net_dev: the soft interface net device | |
716 | */ | |
717 | void batadv_dat_status_update(struct net_device *net_dev) | |
718 | { | |
719 | struct batadv_priv *bat_priv = netdev_priv(net_dev); | |
f138694b | 720 | |
17cf0ea4 ML |
721 | batadv_dat_tvlv_container_update(bat_priv); |
722 | } | |
723 | ||
724 | /** | |
6d030de8 | 725 | * batadv_dat_tvlv_ogm_handler_v1 - process incoming dat tvlv container |
17cf0ea4 ML |
726 | * @bat_priv: the bat priv with all the soft interface information |
727 | * @orig: the orig_node of the ogm | |
728 | * @flags: flags indicating the tvlv state (see batadv_tvlv_handler_flags) | |
729 | * @tvlv_value: tvlv buffer containing the gateway data | |
730 | * @tvlv_value_len: tvlv buffer length | |
731 | */ | |
732 | static void batadv_dat_tvlv_ogm_handler_v1(struct batadv_priv *bat_priv, | |
733 | struct batadv_orig_node *orig, | |
6b5e971a SE |
734 | u8 flags, |
735 | void *tvlv_value, u16 tvlv_value_len) | |
17cf0ea4 ML |
736 | { |
737 | if (flags & BATADV_TVLV_HANDLER_OGM_CIFNOTFND) | |
65d7d460 | 738 | clear_bit(BATADV_ORIG_CAPA_HAS_DAT, &orig->capabilities); |
17cf0ea4 | 739 | else |
65d7d460 | 740 | set_bit(BATADV_ORIG_CAPA_HAS_DAT, &orig->capabilities); |
17cf0ea4 ML |
741 | } |
742 | ||
2f1dfbe1 AQ |
743 | /** |
744 | * batadv_dat_hash_free - free the local DAT hash table | |
745 | * @bat_priv: the bat priv with all the soft interface information | |
746 | */ | |
747 | static void batadv_dat_hash_free(struct batadv_priv *bat_priv) | |
748 | { | |
33af49ad AQ |
749 | if (!bat_priv->dat.hash) |
750 | return; | |
751 | ||
2f1dfbe1 AQ |
752 | __batadv_dat_purge(bat_priv, NULL); |
753 | ||
754 | batadv_hash_destroy(bat_priv->dat.hash); | |
755 | ||
756 | bat_priv->dat.hash = NULL; | |
757 | } | |
758 | ||
759 | /** | |
760 | * batadv_dat_init - initialise the DAT internals | |
761 | * @bat_priv: the bat priv with all the soft interface information | |
fe13c2aa AQ |
762 | * |
763 | * Return: 0 in case of success, a negative error code otherwise | |
2f1dfbe1 AQ |
764 | */ |
765 | int batadv_dat_init(struct batadv_priv *bat_priv) | |
766 | { | |
767 | if (bat_priv->dat.hash) | |
768 | return 0; | |
769 | ||
770 | bat_priv->dat.hash = batadv_hash_new(1024); | |
771 | ||
772 | if (!bat_priv->dat.hash) | |
773 | return -ENOMEM; | |
774 | ||
775 | batadv_dat_start_timer(bat_priv); | |
776 | ||
17cf0ea4 ML |
777 | batadv_tvlv_handler_register(bat_priv, batadv_dat_tvlv_ogm_handler_v1, |
778 | NULL, BATADV_TVLV_DAT, 1, | |
779 | BATADV_TVLV_HANDLER_OGM_CIFNOTFND); | |
780 | batadv_dat_tvlv_container_update(bat_priv); | |
2f1dfbe1 AQ |
781 | return 0; |
782 | } | |
783 | ||
784 | /** | |
785 | * batadv_dat_free - free the DAT internals | |
786 | * @bat_priv: the bat priv with all the soft interface information | |
787 | */ | |
788 | void batadv_dat_free(struct batadv_priv *bat_priv) | |
789 | { | |
17cf0ea4 ML |
790 | batadv_tvlv_container_unregister(bat_priv, BATADV_TVLV_DAT, 1); |
791 | batadv_tvlv_handler_unregister(bat_priv, BATADV_TVLV_DAT, 1); | |
792 | ||
2f1dfbe1 AQ |
793 | cancel_delayed_work_sync(&bat_priv->dat.work); |
794 | ||
795 | batadv_dat_hash_free(bat_priv); | |
796 | } | |
797 | ||
dc1cbd14 | 798 | #ifdef CONFIG_BATMAN_ADV_DEBUGFS |
2f1dfbe1 AQ |
799 | /** |
800 | * batadv_dat_cache_seq_print_text - print the local DAT hash table | |
801 | * @seq: seq file to print on | |
802 | * @offset: not used | |
fe13c2aa AQ |
803 | * |
804 | * Return: always 0 | |
2f1dfbe1 AQ |
805 | */ |
806 | int batadv_dat_cache_seq_print_text(struct seq_file *seq, void *offset) | |
807 | { | |
808 | struct net_device *net_dev = (struct net_device *)seq->private; | |
809 | struct batadv_priv *bat_priv = netdev_priv(net_dev); | |
810 | struct batadv_hashtable *hash = bat_priv->dat.hash; | |
811 | struct batadv_dat_entry *dat_entry; | |
812 | struct batadv_hard_iface *primary_if; | |
2f1dfbe1 AQ |
813 | struct hlist_head *head; |
814 | unsigned long last_seen_jiffies; | |
815 | int last_seen_msecs, last_seen_secs, last_seen_mins; | |
6b5e971a | 816 | u32 i; |
2f1dfbe1 AQ |
817 | |
818 | primary_if = batadv_seq_print_text_primary_if_get(seq); | |
819 | if (!primary_if) | |
820 | goto out; | |
821 | ||
822 | seq_printf(seq, "Distributed ARP Table (%s):\n", net_dev->name); | |
925a6f37 AQ |
823 | seq_puts(seq, |
824 | " IPv4 MAC VID last-seen\n"); | |
2f1dfbe1 AQ |
825 | |
826 | for (i = 0; i < hash->size; i++) { | |
827 | head = &hash->table[i]; | |
828 | ||
829 | rcu_read_lock(); | |
b67bfe0d | 830 | hlist_for_each_entry_rcu(dat_entry, head, hash_entry) { |
2f1dfbe1 AQ |
831 | last_seen_jiffies = jiffies - dat_entry->last_update; |
832 | last_seen_msecs = jiffies_to_msecs(last_seen_jiffies); | |
833 | last_seen_mins = last_seen_msecs / 60000; | |
834 | last_seen_msecs = last_seen_msecs % 60000; | |
835 | last_seen_secs = last_seen_msecs / 1000; | |
836 | ||
be1db4f6 | 837 | seq_printf(seq, " * %15pI4 %14pM %4i %6i:%02i\n", |
2f1dfbe1 | 838 | &dat_entry->ip, dat_entry->mac_addr, |
f7a2bd65 | 839 | batadv_print_vid(dat_entry->vid), |
2f1dfbe1 AQ |
840 | last_seen_mins, last_seen_secs); |
841 | } | |
842 | rcu_read_unlock(); | |
843 | } | |
844 | ||
845 | out: | |
846 | if (primary_if) | |
82047ad7 | 847 | batadv_hardif_put(primary_if); |
2f1dfbe1 AQ |
848 | return 0; |
849 | } | |
dc1cbd14 | 850 | #endif |
5c3a0e55 AQ |
851 | |
852 | /** | |
853 | * batadv_arp_get_type - parse an ARP packet and gets the type | |
854 | * @bat_priv: the bat priv with all the soft interface information | |
855 | * @skb: packet to analyse | |
856 | * @hdr_size: size of the possible header before the ARP packet in the skb | |
857 | * | |
62fe710f | 858 | * Return: the ARP type if the skb contains a valid ARP packet, 0 otherwise. |
5c3a0e55 | 859 | */ |
6b5e971a SE |
860 | static u16 batadv_arp_get_type(struct batadv_priv *bat_priv, |
861 | struct sk_buff *skb, int hdr_size) | |
5c3a0e55 AQ |
862 | { |
863 | struct arphdr *arphdr; | |
864 | struct ethhdr *ethhdr; | |
865 | __be32 ip_src, ip_dst; | |
6b5e971a SE |
866 | u8 *hw_src, *hw_dst; |
867 | u16 type = 0; | |
5c3a0e55 AQ |
868 | |
869 | /* pull the ethernet header */ | |
870 | if (unlikely(!pskb_may_pull(skb, hdr_size + ETH_HLEN))) | |
871 | goto out; | |
872 | ||
873 | ethhdr = (struct ethhdr *)(skb->data + hdr_size); | |
874 | ||
875 | if (ethhdr->h_proto != htons(ETH_P_ARP)) | |
876 | goto out; | |
877 | ||
878 | /* pull the ARP payload */ | |
879 | if (unlikely(!pskb_may_pull(skb, hdr_size + ETH_HLEN + | |
880 | arp_hdr_len(skb->dev)))) | |
881 | goto out; | |
882 | ||
883 | arphdr = (struct arphdr *)(skb->data + hdr_size + ETH_HLEN); | |
884 | ||
93178018 | 885 | /* check whether the ARP packet carries a valid IP information */ |
5c3a0e55 AQ |
886 | if (arphdr->ar_hrd != htons(ARPHRD_ETHER)) |
887 | goto out; | |
888 | ||
889 | if (arphdr->ar_pro != htons(ETH_P_IP)) | |
890 | goto out; | |
891 | ||
892 | if (arphdr->ar_hln != ETH_ALEN) | |
893 | goto out; | |
894 | ||
895 | if (arphdr->ar_pln != 4) | |
896 | goto out; | |
897 | ||
898 | /* Check for bad reply/request. If the ARP message is not sane, DAT | |
899 | * will simply ignore it | |
900 | */ | |
901 | ip_src = batadv_arp_ip_src(skb, hdr_size); | |
902 | ip_dst = batadv_arp_ip_dst(skb, hdr_size); | |
903 | if (ipv4_is_loopback(ip_src) || ipv4_is_multicast(ip_src) || | |
757dd82e MS |
904 | ipv4_is_loopback(ip_dst) || ipv4_is_multicast(ip_dst) || |
905 | ipv4_is_zeronet(ip_src) || ipv4_is_lbcast(ip_src) || | |
906 | ipv4_is_zeronet(ip_dst) || ipv4_is_lbcast(ip_dst)) | |
5c3a0e55 AQ |
907 | goto out; |
908 | ||
b618ad11 MS |
909 | hw_src = batadv_arp_hw_src(skb, hdr_size); |
910 | if (is_zero_ether_addr(hw_src) || is_multicast_ether_addr(hw_src)) | |
911 | goto out; | |
912 | ||
93178018 | 913 | /* don't care about the destination MAC address in ARP requests */ |
b618ad11 MS |
914 | if (arphdr->ar_op != htons(ARPOP_REQUEST)) { |
915 | hw_dst = batadv_arp_hw_dst(skb, hdr_size); | |
916 | if (is_zero_ether_addr(hw_dst) || | |
917 | is_multicast_ether_addr(hw_dst)) | |
918 | goto out; | |
919 | } | |
920 | ||
5c3a0e55 AQ |
921 | type = ntohs(arphdr->ar_op); |
922 | out: | |
923 | return type; | |
924 | } | |
c384ea3e | 925 | |
be1db4f6 AQ |
926 | /** |
927 | * batadv_dat_get_vid - extract the VLAN identifier from skb if any | |
928 | * @skb: the buffer containing the packet to extract the VID from | |
929 | * @hdr_size: the size of the batman-adv header encapsulating the packet | |
930 | * | |
62fe710f SE |
931 | * Return: If the packet embedded in the skb is vlan tagged this function |
932 | * returns the VID with the BATADV_VLAN_HAS_TAG flag. Otherwise BATADV_NO_FLAGS | |
933 | * is returned. | |
be1db4f6 AQ |
934 | */ |
935 | static unsigned short batadv_dat_get_vid(struct sk_buff *skb, int *hdr_size) | |
936 | { | |
937 | unsigned short vid; | |
938 | ||
939 | vid = batadv_get_vid(skb, *hdr_size); | |
940 | ||
941 | /* ARP parsing functions jump forward of hdr_size + ETH_HLEN. | |
942 | * If the header contained in the packet is a VLAN one (which is longer) | |
943 | * hdr_size is updated so that the functions will still skip the | |
944 | * correct amount of bytes. | |
945 | */ | |
946 | if (vid & BATADV_VLAN_HAS_TAG) | |
947 | *hdr_size += VLAN_HLEN; | |
948 | ||
949 | return vid; | |
950 | } | |
951 | ||
cbfc16de LL |
952 | /** |
953 | * batadv_dat_arp_create_reply - create an ARP Reply | |
954 | * @bat_priv: the bat priv with all the soft interface information | |
955 | * @ip_src: ARP sender IP | |
956 | * @ip_dst: ARP target IP | |
957 | * @hw_src: Ethernet source and ARP sender MAC | |
958 | * @hw_dst: Ethernet destination and ARP target MAC | |
959 | * @vid: VLAN identifier (optional, set to zero otherwise) | |
960 | * | |
961 | * Creates an ARP Reply from the given values, optionally encapsulated in a | |
962 | * VLAN header. | |
963 | * | |
964 | * Return: An skb containing an ARP Reply. | |
965 | */ | |
966 | static struct sk_buff * | |
967 | batadv_dat_arp_create_reply(struct batadv_priv *bat_priv, __be32 ip_src, | |
968 | __be32 ip_dst, u8 *hw_src, u8 *hw_dst, | |
969 | unsigned short vid) | |
970 | { | |
971 | struct sk_buff *skb; | |
972 | ||
973 | skb = arp_create(ARPOP_REPLY, ETH_P_ARP, ip_dst, bat_priv->soft_iface, | |
974 | ip_src, hw_dst, hw_src, hw_dst); | |
975 | if (!skb) | |
976 | return NULL; | |
977 | ||
978 | skb_reset_mac_header(skb); | |
979 | ||
980 | if (vid & BATADV_VLAN_HAS_TAG) | |
981 | skb = vlan_insert_tag(skb, htons(ETH_P_8021Q), | |
982 | vid & VLAN_VID_MASK); | |
983 | ||
984 | return skb; | |
985 | } | |
986 | ||
c384ea3e AQ |
987 | /** |
988 | * batadv_dat_snoop_outgoing_arp_request - snoop the ARP request and try to | |
989 | * answer using DAT | |
990 | * @bat_priv: the bat priv with all the soft interface information | |
991 | * @skb: packet to check | |
992 | * | |
62fe710f | 993 | * Return: true if the message has been sent to the dht candidates, false |
93178018 ML |
994 | * otherwise. In case of a positive return value the message has to be enqueued |
995 | * to permit the fallback. | |
c384ea3e AQ |
996 | */ |
997 | bool batadv_dat_snoop_outgoing_arp_request(struct batadv_priv *bat_priv, | |
998 | struct sk_buff *skb) | |
999 | { | |
6b5e971a | 1000 | u16 type = 0; |
c384ea3e | 1001 | __be32 ip_dst, ip_src; |
6b5e971a | 1002 | u8 *hw_src; |
c384ea3e AQ |
1003 | bool ret = false; |
1004 | struct batadv_dat_entry *dat_entry = NULL; | |
1005 | struct sk_buff *skb_new; | |
ab044f8e | 1006 | struct net_device *soft_iface = bat_priv->soft_iface; |
be1db4f6 AQ |
1007 | int hdr_size = 0; |
1008 | unsigned short vid; | |
c384ea3e | 1009 | |
33af49ad AQ |
1010 | if (!atomic_read(&bat_priv->distributed_arp_table)) |
1011 | goto out; | |
1012 | ||
be1db4f6 AQ |
1013 | vid = batadv_dat_get_vid(skb, &hdr_size); |
1014 | ||
1015 | type = batadv_arp_get_type(bat_priv, skb, hdr_size); | |
c384ea3e AQ |
1016 | /* If the node gets an ARP_REQUEST it has to send a DHT_GET unicast |
1017 | * message to the selected DHT candidates | |
1018 | */ | |
1019 | if (type != ARPOP_REQUEST) | |
1020 | goto out; | |
1021 | ||
843314c9 | 1022 | batadv_dbg_arp(bat_priv, skb, hdr_size, "Parsing outgoing ARP REQUEST"); |
c384ea3e | 1023 | |
be1db4f6 AQ |
1024 | ip_src = batadv_arp_ip_src(skb, hdr_size); |
1025 | hw_src = batadv_arp_hw_src(skb, hdr_size); | |
1026 | ip_dst = batadv_arp_ip_dst(skb, hdr_size); | |
c384ea3e | 1027 | |
be1db4f6 | 1028 | batadv_dat_entry_add(bat_priv, ip_src, hw_src, vid); |
c384ea3e | 1029 | |
be1db4f6 | 1030 | dat_entry = batadv_dat_entry_hash_find(bat_priv, ip_dst, vid); |
c384ea3e | 1031 | if (dat_entry) { |
88e48d7b AQ |
1032 | /* If the ARP request is destined for a local client the local |
1033 | * client will answer itself. DAT would only generate a | |
1034 | * duplicate packet. | |
1035 | * | |
1036 | * Moreover, if the soft-interface is enslaved into a bridge, an | |
1037 | * additional DAT answer may trigger kernel warnings about | |
1038 | * a packet coming from the wrong port. | |
1039 | */ | |
cc2f3386 | 1040 | if (batadv_is_my_client(bat_priv, dat_entry->mac_addr, vid)) { |
88e48d7b AQ |
1041 | ret = true; |
1042 | goto out; | |
1043 | } | |
1044 | ||
00311de5 AP |
1045 | /* If BLA is enabled, only send ARP replies if we have claimed |
1046 | * the destination for the ARP request or if no one else of | |
1047 | * the backbone gws belonging to our backbone has claimed the | |
1048 | * destination. | |
1049 | */ | |
1050 | if (!batadv_bla_check_claim(bat_priv, | |
1051 | dat_entry->mac_addr, vid)) { | |
1052 | batadv_dbg(BATADV_DBG_DAT, bat_priv, | |
1053 | "Device %pM claimed by another backbone gw. Don't send ARP reply!", | |
1054 | dat_entry->mac_addr); | |
1055 | ret = true; | |
1056 | goto out; | |
1057 | } | |
1058 | ||
cbfc16de LL |
1059 | skb_new = batadv_dat_arp_create_reply(bat_priv, ip_dst, ip_src, |
1060 | dat_entry->mac_addr, | |
1061 | hw_src, vid); | |
c384ea3e AQ |
1062 | if (!skb_new) |
1063 | goto out; | |
1064 | ||
ab044f8e TK |
1065 | skb_new->protocol = eth_type_trans(skb_new, soft_iface); |
1066 | ||
36d4d68c SE |
1067 | batadv_inc_counter(bat_priv, BATADV_CNT_RX); |
1068 | batadv_add_counter(bat_priv, BATADV_CNT_RX_BYTES, | |
1069 | skb->len + ETH_HLEN + hdr_size); | |
c384ea3e AQ |
1070 | |
1071 | netif_rx(skb_new); | |
1072 | batadv_dbg(BATADV_DBG_DAT, bat_priv, "ARP request replied locally\n"); | |
1073 | ret = true; | |
1074 | } else { | |
93178018 | 1075 | /* Send the request to the DHT */ |
2871734e | 1076 | ret = batadv_dat_send_data(bat_priv, skb, ip_dst, vid, |
c384ea3e AQ |
1077 | BATADV_P_DAT_DHT_GET); |
1078 | } | |
1079 | out: | |
1080 | if (dat_entry) | |
a6416f9f | 1081 | batadv_dat_entry_put(dat_entry); |
c384ea3e AQ |
1082 | return ret; |
1083 | } | |
1084 | ||
1085 | /** | |
1086 | * batadv_dat_snoop_incoming_arp_request - snoop the ARP request and try to | |
1087 | * answer using the local DAT storage | |
1088 | * @bat_priv: the bat priv with all the soft interface information | |
1089 | * @skb: packet to check | |
1090 | * @hdr_size: size of the encapsulation header | |
1091 | * | |
62fe710f | 1092 | * Return: true if the request has been answered, false otherwise. |
c384ea3e AQ |
1093 | */ |
1094 | bool batadv_dat_snoop_incoming_arp_request(struct batadv_priv *bat_priv, | |
1095 | struct sk_buff *skb, int hdr_size) | |
1096 | { | |
6b5e971a | 1097 | u16 type; |
c384ea3e | 1098 | __be32 ip_src, ip_dst; |
6b5e971a | 1099 | u8 *hw_src; |
c384ea3e | 1100 | struct sk_buff *skb_new; |
c384ea3e AQ |
1101 | struct batadv_dat_entry *dat_entry = NULL; |
1102 | bool ret = false; | |
be1db4f6 | 1103 | unsigned short vid; |
c384ea3e AQ |
1104 | int err; |
1105 | ||
33af49ad AQ |
1106 | if (!atomic_read(&bat_priv->distributed_arp_table)) |
1107 | goto out; | |
1108 | ||
be1db4f6 AQ |
1109 | vid = batadv_dat_get_vid(skb, &hdr_size); |
1110 | ||
c384ea3e AQ |
1111 | type = batadv_arp_get_type(bat_priv, skb, hdr_size); |
1112 | if (type != ARPOP_REQUEST) | |
1113 | goto out; | |
1114 | ||
1115 | hw_src = batadv_arp_hw_src(skb, hdr_size); | |
1116 | ip_src = batadv_arp_ip_src(skb, hdr_size); | |
1117 | ip_dst = batadv_arp_ip_dst(skb, hdr_size); | |
1118 | ||
843314c9 | 1119 | batadv_dbg_arp(bat_priv, skb, hdr_size, "Parsing incoming ARP REQUEST"); |
c384ea3e | 1120 | |
be1db4f6 | 1121 | batadv_dat_entry_add(bat_priv, ip_src, hw_src, vid); |
c384ea3e | 1122 | |
be1db4f6 | 1123 | dat_entry = batadv_dat_entry_hash_find(bat_priv, ip_dst, vid); |
c384ea3e AQ |
1124 | if (!dat_entry) |
1125 | goto out; | |
1126 | ||
cbfc16de LL |
1127 | skb_new = batadv_dat_arp_create_reply(bat_priv, ip_dst, ip_src, |
1128 | dat_entry->mac_addr, hw_src, vid); | |
c384ea3e AQ |
1129 | if (!skb_new) |
1130 | goto out; | |
1131 | ||
93178018 ML |
1132 | /* To preserve backwards compatibility, the node has choose the outgoing |
1133 | * format based on the incoming request packet type. The assumption is | |
1134 | * that a node not using the 4addr packet format doesn't support it. | |
c384ea3e AQ |
1135 | */ |
1136 | if (hdr_size == sizeof(struct batadv_unicast_4addr_packet)) | |
e300d314 LL |
1137 | err = batadv_send_skb_via_tt_4addr(bat_priv, skb_new, |
1138 | BATADV_P_DAT_CACHE_REPLY, | |
6c413b1c | 1139 | NULL, vid); |
c384ea3e | 1140 | else |
6c413b1c | 1141 | err = batadv_send_skb_via_tt(bat_priv, skb_new, NULL, vid); |
c384ea3e | 1142 | |
e300d314 | 1143 | if (err != NET_XMIT_DROP) { |
4046b24a | 1144 | batadv_inc_counter(bat_priv, BATADV_CNT_DAT_CACHED_REPLY_TX); |
c384ea3e | 1145 | ret = true; |
4046b24a | 1146 | } |
c384ea3e AQ |
1147 | out: |
1148 | if (dat_entry) | |
a6416f9f | 1149 | batadv_dat_entry_put(dat_entry); |
c384ea3e AQ |
1150 | if (ret) |
1151 | kfree_skb(skb); | |
1152 | return ret; | |
1153 | } | |
1154 | ||
1155 | /** | |
1156 | * batadv_dat_snoop_outgoing_arp_reply - snoop the ARP reply and fill the DHT | |
1157 | * @bat_priv: the bat priv with all the soft interface information | |
1158 | * @skb: packet to check | |
1159 | */ | |
1160 | void batadv_dat_snoop_outgoing_arp_reply(struct batadv_priv *bat_priv, | |
1161 | struct sk_buff *skb) | |
1162 | { | |
6b5e971a | 1163 | u16 type; |
c384ea3e | 1164 | __be32 ip_src, ip_dst; |
6b5e971a | 1165 | u8 *hw_src, *hw_dst; |
be1db4f6 AQ |
1166 | int hdr_size = 0; |
1167 | unsigned short vid; | |
c384ea3e | 1168 | |
33af49ad AQ |
1169 | if (!atomic_read(&bat_priv->distributed_arp_table)) |
1170 | return; | |
1171 | ||
be1db4f6 AQ |
1172 | vid = batadv_dat_get_vid(skb, &hdr_size); |
1173 | ||
1174 | type = batadv_arp_get_type(bat_priv, skb, hdr_size); | |
c384ea3e AQ |
1175 | if (type != ARPOP_REPLY) |
1176 | return; | |
1177 | ||
843314c9 | 1178 | batadv_dbg_arp(bat_priv, skb, hdr_size, "Parsing outgoing ARP REPLY"); |
c384ea3e | 1179 | |
be1db4f6 AQ |
1180 | hw_src = batadv_arp_hw_src(skb, hdr_size); |
1181 | ip_src = batadv_arp_ip_src(skb, hdr_size); | |
1182 | hw_dst = batadv_arp_hw_dst(skb, hdr_size); | |
1183 | ip_dst = batadv_arp_ip_dst(skb, hdr_size); | |
c384ea3e | 1184 | |
be1db4f6 AQ |
1185 | batadv_dat_entry_add(bat_priv, ip_src, hw_src, vid); |
1186 | batadv_dat_entry_add(bat_priv, ip_dst, hw_dst, vid); | |
c384ea3e AQ |
1187 | |
1188 | /* Send the ARP reply to the candidates for both the IP addresses that | |
93178018 | 1189 | * the node obtained from the ARP reply |
c384ea3e | 1190 | */ |
2871734e AQ |
1191 | batadv_dat_send_data(bat_priv, skb, ip_src, vid, BATADV_P_DAT_DHT_PUT); |
1192 | batadv_dat_send_data(bat_priv, skb, ip_dst, vid, BATADV_P_DAT_DHT_PUT); | |
c384ea3e | 1193 | } |
aa143d28 | 1194 | |
c384ea3e AQ |
1195 | /** |
1196 | * batadv_dat_snoop_incoming_arp_reply - snoop the ARP reply and fill the local | |
1197 | * DAT storage only | |
1198 | * @bat_priv: the bat priv with all the soft interface information | |
1199 | * @skb: packet to check | |
93178018 | 1200 | * @hdr_size: size of the encapsulation header |
f202a666 | 1201 | * |
62fe710f | 1202 | * Return: true if the packet was snooped and consumed by DAT. False if the |
f202a666 | 1203 | * packet has to be delivered to the interface |
c384ea3e AQ |
1204 | */ |
1205 | bool batadv_dat_snoop_incoming_arp_reply(struct batadv_priv *bat_priv, | |
1206 | struct sk_buff *skb, int hdr_size) | |
1207 | { | |
9aa5cd79 | 1208 | struct batadv_dat_entry *dat_entry = NULL; |
6b5e971a | 1209 | u16 type; |
c384ea3e | 1210 | __be32 ip_src, ip_dst; |
6b5e971a | 1211 | u8 *hw_src, *hw_dst; |
f202a666 | 1212 | bool dropped = false; |
be1db4f6 | 1213 | unsigned short vid; |
c384ea3e | 1214 | |
33af49ad AQ |
1215 | if (!atomic_read(&bat_priv->distributed_arp_table)) |
1216 | goto out; | |
1217 | ||
be1db4f6 AQ |
1218 | vid = batadv_dat_get_vid(skb, &hdr_size); |
1219 | ||
c384ea3e AQ |
1220 | type = batadv_arp_get_type(bat_priv, skb, hdr_size); |
1221 | if (type != ARPOP_REPLY) | |
1222 | goto out; | |
1223 | ||
843314c9 | 1224 | batadv_dbg_arp(bat_priv, skb, hdr_size, "Parsing incoming ARP REPLY"); |
c384ea3e AQ |
1225 | |
1226 | hw_src = batadv_arp_hw_src(skb, hdr_size); | |
1227 | ip_src = batadv_arp_ip_src(skb, hdr_size); | |
1228 | hw_dst = batadv_arp_hw_dst(skb, hdr_size); | |
1229 | ip_dst = batadv_arp_ip_dst(skb, hdr_size); | |
1230 | ||
9aa5cd79 AP |
1231 | /* If ip_dst is already in cache and has the right mac address, |
1232 | * drop this frame if this ARP reply is destined for us because it's | |
1233 | * most probably an ARP reply generated by another node of the DHT. | |
1234 | * We have most probably received already a reply earlier. Delivering | |
1235 | * this frame would lead to doubled receive of an ARP reply. | |
1236 | */ | |
1237 | dat_entry = batadv_dat_entry_hash_find(bat_priv, ip_src, vid); | |
1238 | if (dat_entry && batadv_compare_eth(hw_src, dat_entry->mac_addr)) { | |
1239 | batadv_dbg(BATADV_DBG_DAT, bat_priv, "Doubled ARP reply removed: ARP MSG = [src: %pM-%pI4 dst: %pM-%pI4]; dat_entry: %pM-%pI4\n", | |
1240 | hw_src, &ip_src, hw_dst, &ip_dst, | |
1241 | dat_entry->mac_addr, &dat_entry->ip); | |
1242 | dropped = true; | |
1243 | goto out; | |
1244 | } | |
1245 | ||
c384ea3e AQ |
1246 | /* Update our internal cache with both the IP addresses the node got |
1247 | * within the ARP reply | |
1248 | */ | |
be1db4f6 AQ |
1249 | batadv_dat_entry_add(bat_priv, ip_src, hw_src, vid); |
1250 | batadv_dat_entry_add(bat_priv, ip_dst, hw_dst, vid); | |
c384ea3e | 1251 | |
9aa5cd79 AP |
1252 | /* If BLA is enabled, only forward ARP replies if we have claimed the |
1253 | * source of the ARP reply or if no one else of the same backbone has | |
1254 | * already claimed that client. This prevents that different gateways | |
1255 | * to the same backbone all forward the ARP reply leading to multiple | |
1256 | * replies in the backbone. | |
1257 | */ | |
1258 | if (!batadv_bla_check_claim(bat_priv, hw_src, vid)) { | |
1259 | batadv_dbg(BATADV_DBG_DAT, bat_priv, | |
1260 | "Device %pM claimed by another backbone gw. Drop ARP reply.\n", | |
1261 | hw_src); | |
1262 | dropped = true; | |
1263 | goto out; | |
1264 | } | |
1265 | ||
c384ea3e AQ |
1266 | /* if this REPLY is directed to a client of mine, let's deliver the |
1267 | * packet to the interface | |
1268 | */ | |
f202a666 AQ |
1269 | dropped = !batadv_is_my_client(bat_priv, hw_dst, vid); |
1270 | ||
1271 | /* if this REPLY is sent on behalf of a client of mine, let's drop the | |
1272 | * packet because the client will reply by itself | |
1273 | */ | |
1274 | dropped |= batadv_is_my_client(bat_priv, hw_src, vid); | |
c384ea3e | 1275 | out: |
f202a666 | 1276 | if (dropped) |
0d15bece | 1277 | kfree_skb(skb); |
9aa5cd79 AP |
1278 | if (dat_entry) |
1279 | batadv_dat_entry_put(dat_entry); | |
f202a666 AQ |
1280 | /* if dropped == false -> deliver to the interface */ |
1281 | return dropped; | |
c384ea3e AQ |
1282 | } |
1283 | ||
1284 | /** | |
1285 | * batadv_dat_drop_broadcast_packet - check if an ARP request has to be dropped | |
93178018 | 1286 | * (because the node has already obtained the reply via DAT) or not |
c384ea3e AQ |
1287 | * @bat_priv: the bat priv with all the soft interface information |
1288 | * @forw_packet: the broadcast packet | |
1289 | * | |
62fe710f | 1290 | * Return: true if the node can drop the packet, false otherwise. |
c384ea3e AQ |
1291 | */ |
1292 | bool batadv_dat_drop_broadcast_packet(struct batadv_priv *bat_priv, | |
1293 | struct batadv_forw_packet *forw_packet) | |
1294 | { | |
6b5e971a | 1295 | u16 type; |
c384ea3e AQ |
1296 | __be32 ip_dst; |
1297 | struct batadv_dat_entry *dat_entry = NULL; | |
1298 | bool ret = false; | |
be1db4f6 AQ |
1299 | int hdr_size = sizeof(struct batadv_bcast_packet); |
1300 | unsigned short vid; | |
c384ea3e | 1301 | |
33af49ad AQ |
1302 | if (!atomic_read(&bat_priv->distributed_arp_table)) |
1303 | goto out; | |
1304 | ||
c384ea3e AQ |
1305 | /* If this packet is an ARP_REQUEST and the node already has the |
1306 | * information that it is going to ask, then the packet can be dropped | |
1307 | */ | |
e2d9ba43 | 1308 | if (batadv_forw_packet_is_rebroadcast(forw_packet)) |
c384ea3e AQ |
1309 | goto out; |
1310 | ||
be1db4f6 AQ |
1311 | vid = batadv_dat_get_vid(forw_packet->skb, &hdr_size); |
1312 | ||
1313 | type = batadv_arp_get_type(bat_priv, forw_packet->skb, hdr_size); | |
c384ea3e AQ |
1314 | if (type != ARPOP_REQUEST) |
1315 | goto out; | |
1316 | ||
be1db4f6 AQ |
1317 | ip_dst = batadv_arp_ip_dst(forw_packet->skb, hdr_size); |
1318 | dat_entry = batadv_dat_entry_hash_find(bat_priv, ip_dst, vid); | |
c384ea3e AQ |
1319 | /* check if the node already got this entry */ |
1320 | if (!dat_entry) { | |
1321 | batadv_dbg(BATADV_DBG_DAT, bat_priv, | |
1322 | "ARP Request for %pI4: fallback\n", &ip_dst); | |
1323 | goto out; | |
1324 | } | |
1325 | ||
1326 | batadv_dbg(BATADV_DBG_DAT, bat_priv, | |
1327 | "ARP Request for %pI4: fallback prevented\n", &ip_dst); | |
1328 | ret = true; | |
1329 | ||
1330 | out: | |
1331 | if (dat_entry) | |
a6416f9f | 1332 | batadv_dat_entry_put(dat_entry); |
c384ea3e AQ |
1333 | return ret; |
1334 | } |